UNIT EXPERIENCED AN AUTOMATIC REACTOR SCRAM DURING A PLANNED SHUTDOWN“During a planned shutdown in preparation for refueling outage C1R13, shortly after tripping the main turbine, an automatic reactor scram occurred due to high reactor steam dome pressure. Preliminarily, per the plant process computer, the reactor pressure was observed to reach approximately 1074 psig approximately 26 seconds after main steam bypass valves unexpectedly closed. An investigation will be conducted to determine the cause of the bypass valve closure and reactor scram. No safety relief valves lifted as a result of the pressure increase.”This event is being reported under 10 CFR 50.72(b)(2)(iv)(B) as an event or condition that results in actuation of the reactor protection system when the reactor was critical.”

The licensee is manually controlling the steam bypass valves to remove decay heat via the main condenser. All control rods fully inserted. The Unit is in a normal shutdown electrical lineup.

Clinton Power Station began operating April 24, 1987 and reached 100% capacity on September 15, 1987.

After more than a decade of operation the plant’s original owner, Illinois Power, deduced that it was not economical to own and operate only one nuclear generating station. They subsequently sold Clinton Generating Station to Exelon Corporation for a more modest price of $40 million dollars, with the purchase including the fuel in the reactor vessel and responsibility of all the radioactive waste in the spent fuel storage pool.

In January 2010, GE-Hitachi announced that the station will begin producing cobalt-60. The technology is soon to be installed at the Clinton boiling water reactor during Clinton’s planned maintenance and refueling outage in order to produce cobalt-60.

It is produced by inserting a ‘target’ rod rich in non-radioactive cobalt-59 into a reactor core where free neutrons will be captured, turning cobalt-59 into cobalt-60. After retrieval from the core, processing can extract the cobalt-60 for manufacture into a useful radiation source.

Inspired by the nearby power station, Clinton radio stationWHOW changed its motto to “WHOW, your radio active station” in April 1989.